An Evolutionary Economic Analysis of Energy Transitions

Evolutionary economics offers clear insights into the mechanisms that underlie innovations, structural change and transitions. It is therefore of great value for the framing of policies aimed at fostering a transition to a sustainable development. This paper offers an overview of the main insights of evolutionary economics and derives core concepts, namely ‘diversity’, ‘innovation’, ‘selection environment’, ‘bounded rationality’, ‘path dependence and lock-in’, and ‘coevolution’. These concepts are subsequently used to formulate guidelines for the role of the government and the design of public policies, such as the learning from historical technological pathways and the creation of an extended level playing field. In addition, the developments of certain energy technologies are examined in detail within the adopted evolutionary economics framework. Three particular technologies received attention, namely fuel cells, nuclear fusion, and photovoltaic cells.

An Analysis of Particle Swarm Optimizers

Many scientific, engineering and economic problems involve the optimisation of a set of parameters. These problems include examples like minimising the losses in a power grid by finding the optimal configuration of the components, or training a neural network to recognise images of people's faces. Numerous optimisation algorithms have been proposed to solve these problems, with varying degrees of success. The Particle Swarm Optimiser (PSO) is a relatively new technique that has been empirically shown to perform well on many of these optimisation problems. This thesis presents a theoretical model that can be used to describe the long-term behaviour of the algorithm. An enhanced version of the Particle Swarm Optimiser is constructed and shown to have guaranteed convergence on local minima. This algorithm is extended further, resulting in an algorithm with guaranteed convergence on global minima. A model for constructing cooperative PSO algorithms is developed, resulting in the introduction of two new PSO-based algorithms. Empirical results are presented to support the theoretical properties predicted by the various models, using synthetic benchmark functions to investigate specific properties. The various PSO-based algorithms are then applied to the task of training neural networks, corroborating the results obtained on the synthetic benchmark functions.Thesis (PhD)--University of Pretoria, 2007.Computer ScienceUnrestricte

A device-free locator using computer vision techniques

Device-free locators allow the user to interact with a system without the burden of being physically in contact with some input device or without being connected to the system with cables. This thesis presents a device-free locator that uses computer vision techniques to recognize and track the user's hand. The system described herein uses a video camera to capture live video images of the user, which are segmented and processed to extract features that can be used to locate the user's hand within the image. Two types of features, namely moment based invariants and Fourier descriptors, are compared experimentally. An important property of both these techniques is that they allow the recognition of hand-shapes regardless of affine transformation, e.g. rotation within the plane or scale changes. A neural network is used to classify the extracted features as belonging to one of several hand signals, which can be used in the locator system as 'button clicks' or mode indicators. The Siltrack system described herein illustrates that the above techniques can be implemented in real-time on standard hardware.Dissertation (MSc (Computer Science))--University of Pretoria, 2007.Computer Scienceunrestricte

Experimental studies to improve the reliability and validity of regulatory judgments on health care in the Netherlands: a randomized controlled trial and before and after case study

Rationale, aims and objectives We examined the effect of two interventions on both the reliability and validity of regulatory judgments: adjusting the regulatory instrument and attending a consensus meeting. Method We adjusted the regulatory instrument. With a randomized controlled trial (RCT) we examined the effect of the adjustments we made to the instrument. In the consensus meeting inspectors discussed cases and had to reach consensus about the order of the cases. We used a before and after case study to assess the effect of the consensus meeting. We compared the judgments assigned in the RCT with the unadjusted instrument with the judgments assigned with the unadjusted instrument after the consensus meeting. Moreover we explored the effect of increasing the number of inspectors per regulatory visit based on the estimates of the two interventions. Results The consensus meeting improved the agreement between inspectors; the variance between inspectors was smallest (0.03) and the reliability coefficient was highest (0.59). Validity is assessed by examining the relation between the assigned judgments and the corporate standard and expressed by a correlation coefficient. This coefficient was highest after the consensus meeting (0.48). Adjustment of the instrument did not increase reliability and validity coefficients. Conclusions Participating in a consensus meeting improved reliability and validity. Increasing the number of inspectors resulted in both higher reliability and validity values. Organizing consensus meetings and increasing the number of inspectors per regulatory visit seem to be valuable interventions for improving regulatory judgment

A convergence proof for the particle swarm optimiser

The Particle Swarm Optimiser (PSO) is a population based stochastic optimisation algorithm, empirically shown to be efficient and robust. This paper provides a proof to show that the original PSO does not have guaranteed convergence to a local optimum. A flaw in the original PSO is identified which causes stagnation of the swarm. Correction of this flaw results in a PSO algorithm with guaranteed convergence to a local minimum. Further extensions with provable global convergence are also described. Experimental results are provided to elucidate the behavior of the modified PSO as well as PSO variations with global convergence.http://www.iospress.nl/loadtop/load.php?isbn=0169296

Het ene oordeel is het andere niet: Kwantitatieve analyse van de variatie bij IGZ-Inspecteurs

DOEL\ud Onderzoek naar de variatie in oordelen tussen inspecteurs van de Inspectie voor de Gezondheidszorg (IGZ) in het systeem van gefaseerd toezicht op de verpleeghuiszorg en naar de relatie tussen het type oordeel en de aan- of afwezigheid van onderbouwing daarbij.\ud \ud OPZET \ud Descriptief, kwantitatief, retrospectief.\ud \ud METHODE\ud In totaal werden 4914 oordelen met bijbehorende onderbouwingen van 26 inspecteurs uit 182 toezichtrapporten geanalyseerd. De oordelen waren in 2005 en 2006 gegeven op 25 criteria voor verantwoorde zorg in verpleeghuizen. Om de inspecteurs en hun oordelen over verschillende instellingen te kunnen vergelijken, werd met covariantieanalyse statistisch gecorrigeerd voor instellingskenmerken.\ud \ud RESULTATEN\ud Er waren statistisch significante verschillen in beoordeling tussen de inspecteurs. Na correctie voor instellingskenmerken bleven voor 14 van de 25 criteria significante verschillen bestaan. Tevens bleek de aanwezigheid van een onderbouwing bij een oordeel zowel afhankelijk te zijn van de inspecteur als van het gegeven oordeel.\ud \ud CONCLUSIE \ud Beoordelaarsverschillen tussen inspecteurs spelen een rol in de tweede fase van het gefaseerd toezicht op de verpleeghuizen. De IGZ zal resultaten van dit onderzoek gebruiken om haar toezicht verder te ontwikkelen

Peroneal nerve: normal anatomy and pathologic findings on routine MRI of the knee

Background : Peroneal nerve lesions are not common and are often exclusively assessed clinically and electromyographically. Methods : On a routine MR examination without dedicated MR-neurography sequences the peroneal nerve can readily be assessed. Axial T1-weighted sequences are especially helpful as they allow a good differentiation between the nerve and the surrounding fat. Results : The purpose of this article is to review the normal anatomy and pathologic conditions of the peroneal nerve around the knee. Conclusion : In the first part the variable anatomy of the peroneal nerve around the knee will be emphasized, followed by a discussion of the clinical findings of peroneal neuropathy and general MR signs of denervation. Six anatomical features may predispose to peroneal neuropathy: paucity of epineural tissue, biceps femoris tunnel, bifurcation level, superficial course around the fibula, fibular tunnel and finally the additional nerve branches. In the second part we discuss the different pathologic conditions: accidental and surgical trauma, and intraneural and extraneural compressive lesions. Teaching Points : • Six anatomical features contribute to the vulnerability of the peroneal nerve around the knee. • MR signs of muscle denervation within the anterior compartment are important secondary signs for evaluation of the peroneal nerve. • The most common lesions of the peroneal nerve are traumatic or compressive. • Intraneural ganglia originate from the proximal tibiofibular joint. • Axial T1-weighted images are the best sequence to visualise the peroneal nerve on routine MRI

Experimental studies to improve the reliability and validity of regulatory judgments on health care in the Netherlands: A randomized controlled trial and before and after case study

Rationale, aims and objectives We examined the effect of two interventions on both the reliability and validity of regulatory judgments: adjusting the regulatory instrument and attending a consensus meeting. Method We adjusted the regulatory instrument. With a randomized controlled trial (RCT) we examined the effect of the adjustments we made to the instrument. In the consensus meeting inspectors discussed cases and had to reach consensus about the order of the cases. We used a before and after case study to assess the effect of the consensus meeting. We compared the judgments assigned in the RCT with the unadjusted instrument with the judgments assigned with the unadjusted instrument after the consensus meeting. Moreover we explored the effect of increasing the number of inspectors per regulatory visit based on the estimates of the two interventions. Results The consensus meeting improved the agreement between inspectors; the variance between inspectors was smallest (0.03) and the reliability coefficient was highest (0.59). Validity is assessed by examining the relation between the assigned judgments and the corporate standard and expressed by a correlation coefficient. This coefficient was highest after the consensus meeting (0.48). Adjustment of the instrument did not increase reliability and validity coefficients. Conclusions Participating in a consensus meeting improved reliability and validity. Increasing the number of inspectors resulted in both higher reliability and validity values. Organizing consensus meetings and increasing the number of inspectors per regulatory visit seem to be valuable interventions for improving regulatory judgments

Adaptive threshold-based shadow masking for across-date settlement classification of panchromatic QuickBird images

Multitemporal land-use analysis is becoming increasingly important for the effective management of earth resources. Despite that, consistent differences in the viewing and illumination geometry in satellite-borne imagery introduce some issues in the creation of land-use classification maps. The focus of this study is settlement classification with high-resolution panchromatic acquisitions, using texture features to distinguish between settlement classes. The important multitemporal variance component of shadow is effectively removed before feature determination, which allows for minimum-supervision across-date classification. Shadow detection based on local adaptive thresholding is employed and experimentally shown to outperform existing fixed threshold shadow detectors in increasing settlement classification accuracy. Both same and across-date settlement accuracies are significantly improved with shadow masking during feature calculation. A statistical study was performed and found to support the hypothesis that the increased accuracy is due to shadow masking specifically.National Research Foundationhttp://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=8859hb2014ai201

The effects of segmentation-based shadow removal on across-date settlement type classification of panchromatic QuickBird images

Settlement classifiers for multitemporal satellite image analysis have to overcome numerous difficulties related to across-date variances in viewing- and illumination geometry. Shadow anisotropy is a prominent contributing factor in classifier inaccuracy, so methods are introduced in this study to enable minimum-supervision classifier design that mitigate the effects of shadow profile differences. A segmentation-based shadow detector is proposed that utilizes a panchromatic segment merging algorithm with parameters that are robust against dynamic range variances seen in multitemporal imagery. The proposed shadow detector improves on the settlement classification accuracy achieved by fixed threshold detection paired with shadow removal in the presented case-study. The relationship between shadow detection accuracy and settlement classification accuracy is investigated, and it is shown that shadow removal produces greater settlement accuracy improvements for across-date experiments specifically.National Research Foundation (NRF)http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?reload=true&punumber=4609443hb2013ai201